Here's the one that inspired me to ask:
$sql = "
create table #foo (variable1 char(20),
variable2 char(30) null)
/*
comments make it slow
*/
";
my $comment = qr/(?:\/\*.*?\*\/)/; # Simple
+match of C-style comment
my $sp = qr/(?:\s*$comment?\s*)*/; # This ju
+st looks for /* comments */, with whitespace on either side.
# Sinc
+e comments can be anywhere, use this anywhere whitespace is allowed.
# The parens don't capture
+, so it won't affect your $1, $2 counts.
my $header = qr/create${sp}table${sp}\#?\w+${sp}\(${sp}/i; # "create
+ table foo (", where table name may have a # mark
my $name = qr/[\#\w]+${sp}/; # Variabl
+e name, can contain # mark
my $type = qr/\w+${sp}/; # Variabl
+e type (e.g. 'char', 'number')
my $op_char = qr/(?:\([\d\s,]+\)${sp})?/; # Bounds
+for array types, can be multidimensional (e.g. '(10, 20)', '(30)')
my $words = qr/(?:[\w]+(?:\([^\)]*\))?[${sp})]*)*/; # Text af
+ter variable type -- may be 'null', 'not null', a 'check' block, etc.
my $subst = qr/${sp}\{[^\}]+\}${sp}/; # Substit
+ution placeholder -- some text in {curlies}
my $decl = qr/($name $type $op_char $words)/x; # A compl
+ete variable declaration
my $comma = qr/,${sp}/; # Literal
+ comma, with possible trailing space
my $rest = qr/\)${sp}/; # Closing
+ the block with a close-paren
if ($sql =~ /
($header)
((?: $decl $comma | $subst $comma | $subst)*
(?: $decl | $subst))
($rest)
/x) {
print "Match!\n";
print "1: >>>$1<<<\n";
print "2: >>>$2<<<\n";
}
It takes about 45 seconds on my box. The longer the comment, the longer the runtime.
---
A fair fight is a sign of poor planning.
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